If the thought of doing battle with an army of cute-yet-deadly monsters to save a leafy world from dark forces piques your interest then Monster Legacy could be for you.

Unlike many other titles in this RPG class Monster Legacy works on a free model where the user never needs to spend a penny to complete the game. It's an interesting choice at a time when more and more gaming companies are squeezing micro-payments into their mobile games.

We got stuck into the game on iOS, where it's available on iPhone and iPad for free from today. Here's what we thought.

The kid gloves are off

While Monster Legacy might look like a game for children, it's got a lot of depth that will appeal to button-bashers of all ages. In fact we found it pretty addictive.

Players battle through the world of Arborea, trying to save it from the evil Lord Ardur who uses monsters to do bad. Keepers are the main characters, of which there is a boy or girl to chose from. These guys are able to "keep" monsters and use them in battles against other beasts, ultimately capturing their foes to build a small army. Yes it's reminiscent of Pokémon, but with a far more Skyrim-meets-Game-of-Thrones magical feel to it - in its own cartoon way.

While making comparisons, the game has a very Lord of the Rings style soundtrack that's both calming and exciting in equal measures. It's perfect for this world where exploring feels adventurous but at the same time fun as a casual gamer. Ideal for the free-play mobile model.

It's obvious the game, made by Outplay Entertainment, is from a young team. There are some great, fun references to films and comics. One character at the start, enquiring about the protagonist's powers asks: "Do you have to flame on or something?" referencing the Fantastic Four.

Earn or pay freedom

The interesting thing about Monster Legacy is the choices offered to gamers. The focused, possibly frugal gamer, can play through the entire game without spending a penny. But should a user want to speed up the process, say by building a house faster to get more upgrades, they can pay in gems or coins. These can be earned by playing the game or bought with real-world money.

So users who want to skip ahead, or cheat as some others might say, can do so by paying. Alternatively they can spend more time fighting and earning in order to pay their way to a speedier victory. The point is gamers aren't forced to pay in order to progress through the game.

One area that's tempting to buy gems for is getting trappers. These are what capture a new monster after it's defeated. The better the trapper, the more likely it will trap the monster. Winning a battle and then losing the monster because of a cheap trapper can be frustrating. If gem supply is short a real-world cash top up here is very tempting indeed.

Paying in time is the only forced charge though. Playing for five days in a row results in a reward of a new monster, for example. But in our experience the game is addictive enough to keep coming back even without reward incentives.

Of course we've not been playing it for the long haul and some games of this type do end up leaving the user waiting before they can continue with enough credit. In this instance we were reassured by its makers that is not the case.

Pricing is pretty standard with the cheapest coin pack at £3 for 10,000 and the most expensive at £70 for 350,000. It's similar for gems which cost £3 for 100 or £70 for 5000, with plenty of options in between for both. Buying a monster, to give some perspective, starts at 10 gems. Buying a trap starts at 300 coins.

Arborea expanse

For a free iOS game the scope of Monster Legacy is impressive. There are over 20 levels and 70 quests to enjoy in the game with over 100 unique monsters to battle and capture. And each monster has different attacks which come in the form of physical, magical, drain, and special. Magic is fun to use as it involves tapping on a bar at the right time for the perfect attack - a bit like hitting a shot in a virtual golf game.

Users can have up to three monsters equipped with them at a time and are able to switch between them. Since different creatures have different elemental powers it's advisable to have one of each where possible. Water beasties, for example, work well against fire sorts.

Monsters can be stored on ranches which are available to be bought as users progress through the game and level-up. Changing out the three companions is done through here, where they can rest and rejuvenate. Users even have the option to customise their ranch by buying extras like banners, trees and torches for game world coins.

Social battlefield

The game, like most mobile titles, is all about sharing socially. After every battle users are given the opportunity to "Share with Friends" on Facebook. This could be used as an ego massager for some or a genuinely competitive field of play for others. Either way it's a promotional win for Monster Legacy.

Monster Legacy has clearly had a lot of time put into it by a passionate team of developers. That heart-felt creativity comes across in a well thought out and immersive game that gives a depth far beyond most free, and even paid for, games.

If you have an iOS device and enjoy role-playing games we'd recommend you give Monster Legacy a go.